L6599AD STMicroelectronics, L6599AD Datasheet - Page 13

• Manufacturer Part Number: L6599AD
• Description: IC RESONANT CONVRTR CTRLR 16SOIC
• Manufacturer: STMicroelectronics

Specifications of L6599AD

• Applications: Resonant Converter Controller
• Voltage - Supply: 8.85 V ~ 16 V
• Current - Supply: 3.5mA
• Operating Temperature: 0°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 16
• Number Of Outputs: Single Output
• Topology: Half-Bridge
• Output Voltage: 1.5 V
• Output Current: 800 mA
• Switching Frequency: 500 KHz
• Duty Cycle (max): 50 %
• Operating Supply Voltage: 8.85 V to 16 V
• Supply Current: 2 mA
• Maximum Operating Temperature: + 150 C
• Minimum Operating Temperature: - 40 C
• Fall Time: 30 ns
• Mounting Style: SMD/SMT
• Output Power: 0.83 W
• Rise Time: 60 ns
• Synchronous Pin: No
• For Use With: 497-10542 - BOARD EVAL BASED ON L6599497-8429 - BOARD ADAPTER L6599/STP12NM50N497-5496 - EVAL BOARD FOR L6599
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Input: -
• Lead Free Status / Rohs Status: Compliant

L6599A
6.1
Figure 4.
Oscillator
The oscillator is programmed externally by means of a capacitor (CF), connected from pin 3
(CF) to ground, that will be alternately charged and discharged by the current defined with
the network connected to pin 4 (RFmin). The pin provides an accurate 2 V reference with
about 2 mA source capability and the higher the current sourced by the pin is, the higher the
oscillator frequency will be. The block diagram of
that explains the operation.
The network that loads the RFmin pin generally comprises three branches:
1.
2.
3.
A resistor RFmin connected between the pin and ground that determines the minimum
operating frequency;
a resistor RFmax connected between the pin and the collector of the (emitter-
grounded) phototransistor that transfers the feedback signal from the secondary side
back to the primary side; while in operation, the phototransistor will modulate the
current through this branch - hence modulating the oscillator frequency - to perform
output voltage regulation; the value of RFmax determines the maximum frequency the
half-bridge will be operated at when the phototransistor is fully saturated;
an R-C series circuit (CSS+RSS) connected between the pin and ground that enables
to set up a frequency shift at start-up (see
contribution of this branch is zero during steady-state operation.
Typical system block diagram
Doc ID 15308 Rev 4
Section 6.3:
Figure 5
shows a simplified internal circuit
Soft-start). Note that the
Application information
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